From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7787CC4345F for ; Tue, 30 Apr 2024 13:36:15 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 055396B0092; Tue, 30 Apr 2024 09:36:15 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 005116B0093; Tue, 30 Apr 2024 09:36:14 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DE77B6B0096; Tue, 30 Apr 2024 09:36:14 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id C0EEE6B0092 for ; Tue, 30 Apr 2024 09:36:14 -0400 (EDT) Received: from smtpin23.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 6A499C0520 for ; Tue, 30 Apr 2024 13:36:14 +0000 (UTC) X-FDA: 82066297068.23.FF1D5EE Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf02.hostedemail.com (Postfix) with ESMTP id BFC9980010 for ; Tue, 30 Apr 2024 13:36:11 +0000 (UTC) Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=JhISrNFA; dmarc=pass (policy=none) header.from=redhat.com; spf=pass (imf02.hostedemail.com: domain of peterx@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=peterx@redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1714484171; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=X39GiTLDBKMPfoBDISZFmIycGpaQv/DxiE0jSscvhBo=; b=p78QPTnxepAEI/caLA3AOTXdnMXHNXisyk7pedV087WbkO7JSEH3+3wZX7jYsMKxrlSPXi 96VfRx/ojSNCSStVkrj8t2V3PhvLlRtFGw8UBdRQIoZBw5ZA0Q1vu4SWqgpcdZ60dGcU8Z 5RurZlt1q1W4Eduj3Sf26lph11ljPLQ= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1714484171; a=rsa-sha256; cv=none; b=3CsAz+0LzwnqAA8yhSzU8zwhw7XRsFTLbZ3bpA59nTNhD8+51IdCRxt0SFYrfmcca/Xazp 7qM5GxrPtSMFucvvKjTCnaVgWa1xfQtWO7VpCpaeVAkqDXN52m/9yFXh9C3jIjdg12PQaA MhJ8LOUu6tNkOIYkBMulLc4PUrYl7Sg= ARC-Authentication-Results: i=1; imf02.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=JhISrNFA; dmarc=pass (policy=none) header.from=redhat.com; spf=pass (imf02.hostedemail.com: domain of peterx@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=peterx@redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1714484171; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=X39GiTLDBKMPfoBDISZFmIycGpaQv/DxiE0jSscvhBo=; b=JhISrNFATlAQ20U6mBjRyNUH44BHdYBLtfctnuyadpL68Zoqf/tNylUmeJh4KVSQjKW6ce whc5UAr3Qw/OHolgeZoXHmbvWZfeLP3n0NmsWA3f5CW1CoPnTFiXBMPqlIVT3OVWXSiFIt as0WMA31A7Kdk6QfhGV3a+ax141Xv5M= Received: from mail-qv1-f72.google.com (mail-qv1-f72.google.com [209.85.219.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-357-exujqrGiPcKwwrp7hixgAQ-1; Tue, 30 Apr 2024 09:36:09 -0400 X-MC-Unique: exujqrGiPcKwwrp7hixgAQ-1 Received: by mail-qv1-f72.google.com with SMTP id 6a1803df08f44-6a0afbead51so5039206d6.3 for ; Tue, 30 Apr 2024 06:36:09 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1714484169; x=1715088969; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=X39GiTLDBKMPfoBDISZFmIycGpaQv/DxiE0jSscvhBo=; b=EI3ufPiq2wgxcPAacDwkihFhWqIEGbfVV5A45lv+x9UTNvMVMXqCQkhW2nHAVA5s3U Ic9cRCg+hgceqFFqA3VMS5LzuTCtnPRitIOgDwGf0bYBihJKYXxCsYZQIWKWohyGP3pI dlNUVjO6ArATRwoYSooSiPXwKTkYa91GqOT07IW+sAShq71Yqioyk+ejEpuAX+zQWF7/ afPs9gONLo11Vi8Cv8WSC/10g4Kxbkz2NA5hWro1+ta/xxbbKhUJAQO/SrQVC5aB9fUg 9JMwhqBuB247Or4OQX7+SQ5LPZlTspEa49ve5NWRmiW0fp0vupdY2ykHFV1375DEwlVn SL1A== X-Forwarded-Encrypted: i=1; AJvYcCWoeuOUGeOZbgYWK3zIjONxnkAZhaGVaQzMmaYENsHtcgv957RcSHz8Kht8Fd11+Liewpm/bC0TvOqEel/a9u6+6kI= X-Gm-Message-State: AOJu0YwtI2bV7RDBLF3cnWTEkb9naLue3bcFAysojjVobr+W9YGOl4Gu oNU9/ywjKXstEY7MYVtqZmBB0rZs1R56ItMmC9IadVt+fCoictnOUJCvIyk/0jDrlXJWH6A859j ZodtVwrt02/1X8oWccdFbGFtpAkTnedvsScln0+Z+8p7KL/5q X-Received: by 2002:a05:6214:411b:b0:699:dfe:6015 with SMTP id kc27-20020a056214411b00b006990dfe6015mr14696151qvb.5.1714484168646; Tue, 30 Apr 2024 06:36:08 -0700 (PDT) X-Google-Smtp-Source: AGHT+IESpSTho+aha4lI1SDbS2XZA+HSwgqi2ttcjxIWV9PibJjPOqo5Au0EYQEDH29ebG39tMI31Q== X-Received: by 2002:a05:6214:411b:b0:699:dfe:6015 with SMTP id kc27-20020a056214411b00b006990dfe6015mr14696112qvb.5.1714484167928; Tue, 30 Apr 2024 06:36:07 -0700 (PDT) Received: from x1n (pool-99-254-121-117.cpe.net.cable.rogers.com. [99.254.121.117]) by smtp.gmail.com with ESMTPSA id z15-20020a0cf00f000000b0069942e76d99sm11384559qvk.48.2024.04.30.06.36.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 30 Apr 2024 06:36:07 -0700 (PDT) Date: Tue, 30 Apr 2024 09:36:05 -0400 From: Peter Xu To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, Andrew Morton , Shuah Khan Subject: Re: [PATCH v1] selftests: mm: gup_longterm: test unsharing logic when R/O pinning Message-ID: References: <20240430131508.86924-1-david@redhat.com> MIME-Version: 1.0 In-Reply-To: <20240430131508.86924-1-david@redhat.com> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: BFC9980010 X-Stat-Signature: 9isyrr3jkoe96w6u9st3risrkhimzcmu X-Rspam-User: X-HE-Tag: 1714484171-225321 X-HE-Meta: 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 pFJbrHkz Sx+KMF8PeqyODGCB3QOjr1JcKPrCSHeVBj7xVXafcan5WOxENFTyPqclShiC6iLDCHLrDIaeZsYglVFsfm1+swdfTxxn/20cg6jLwvso88Y+Urn3Ctm7H7e2KGpf915TBW2LG X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, Apr 30, 2024 at 03:15:08PM +0200, David Hildenbrand wrote: > In our FOLL_LONGTERM tests, we prefault the page tables for the GUP-fast > test cases to be able to find a PTE and exercise the "longterm pinning > allowed" logic on the GUP-fast path where possible. > > For now, we always prefault the page tables writable, resulting in PTEs > that are writable. > > Let's cover more cases to also test if our unsharing logic works as > expected (and is able to make progress when there is nothing to unshare) > by mprotect'ing the range R/O when R/O-pinning, so we don't get PTEs > that are writable. > > This change would have found an issue introduced by commit a12083d721d7 > ("mm/gup: handle hugepd for follow_page()"), whereby R/O pinning was not > able to make progress in all cases, because unsharing logic was not > provided with the VMA to decide at some point that long-term R/O pinning > a !anon page is fine. > > Cc: Andrew Morton > Cc: Shuah Khan > Cc: Peter Xu > Signed-off-by: David Hildenbrand Acked-by: Peter Xu Thanks, -- Peter Xu